The Association Of Maternal Serum Lead Levels During Pregnancy With Risk Of Preterm Birth And SGA

Background Lead(Pb)is a well-known developmental toxicant.The relationship between serum lead levels with risk of preterm birth and small for gestational age(SGA)remains to be determined.Objective The aim of the present study was to analyze the association between maternal serum Pb level with risk of preterm birth and SGA in a population-based birth cohort study.Methods The present study analyzed a sub-study of the China-Anhui Birth Cohort that recruited 3125 eligible mother-and-singleton-offspring pairs.Maternal serum Pb level during pregnancy was measured by graphite furnace atomic absorption spectrometry.All subjects were classified into three groups by tertile division according to serum Pb level: Low-Pb(L-Pb,<1.18 μg/dl),Medium-Pb(M-Pb,1.18-1.70 μg /dl),and High-Pb(H-Pb,≥1.71 μg /dl).The proportions of maternal and neonatal characteristics and the rate for preterm birth among different groups were analyzed using the chi-square test.For multiple comparisons,we used one-way ANOVA.The odds ratios(OR)and 95% confidence intervals(CI)for the association between maternal serum lead level and risk of preterm birth were estimated using multiple logistic regression models.Results There was no difference on birth length,head circumference and chest circumference among different groups.The rate of preterm birth was 2.8% among subjects with L-Pb,6.1% among subjects with M-Pb,and 8.1% among subjects with H-Pb,respectively.After controlling confounding factors,the adjusted OR for preterm birth was 2.33(95%CI: 1.49,3.65)among subjects with M-Pb and 3.09(95%CI: 2.01,4.76)among subjects with H-Pb.Lead exposure during pregnancy increases the risk of preterm birth.Moreover,the adjusted OR of late preterm birth was 3.51(95%CI: 1.92,6.44)in subjects with M-Pb and 4.62(95%CI: 2.56,8.34)in subjects with H-Pb.Maternal serum Pb level was only associated with increased risk of late preterm birth.The rate of SGA was 6.2% in subjects with L-Pb,8.7% in subjects with M-Pb,and 10.1% in subjects with H-Pb,respectively.The adjusted OR of SGA was 1.45(95%CI: 1.04,2.02)in subjects with M-Pb and 1.69(95%CI: 1.22,2.34)in subjects with H-Pb.Interestingly,the rate of SGA infants was elevated only in subjects with H-Pb in the first trimester(adjusted OR: 2.13;95%CI: 1.24,3.38).Maternal lead exposure during pregnancy increase the risk of SGA in girls(adjusted OR: 1.68;95%CI: 1.12,2.54).Conclusion Collectively,exposure to lead during pregnancy increase the risk of premature birth in the Chinese population and maternal serum Pb level was only associated with increased risk of late preterm birth.H-Pb in the first trimester elevate the rate of SGA infants.Maternal lead exposure during pregnancy increase the risk of SGA in girls.